Botanically speaking:
* True nuts: are single-seeded fruits with a hard, dry shell. They develop from a single ovary and are enclosed by a tough, protective husk. Examples include acorns, chestnuts, hazelnuts, and walnuts.
* Trees: are woody plants with a single, tall trunk.
So, based on these definitions, not all true nuts grow on trees.
* Peanuts: are actually legumes, not nuts. They grow underground on a plant that is technically a vine.
* Cashews: grow on a tree, but the cashew "nut" is actually the seed of a kidney-shaped fruit called a cashew apple.
However, in culinary terms:
* Nuts: often refer to any edible seed or fruit with a hard shell, regardless of their botanical classification. This includes things like peanuts, cashews, pistachios, and almonds (which are technically the seeds of stone fruits).
So, the answer to your question depends on how you define "nut" and "tree."
In a botanical sense, not all true nuts grow on trees. But in culinary terms, most of the nuts we eat come from trees.
